This section is intended to provide a background or context to the invention disclosed below. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise explicitly indicated herein, what is described in this section is not prior art to the description in this application and is not admitted to be prior art by inclusion in this section. Abbreviations that may be found in the specification and/or the drawing figures are defined below at the end of the specification but prior to the claims.
Wireless traffic volumes are dramatically outstripping macro cellular capability. One technique for providing improved traffic volumes is to add smaller cells to an area. For instance, a macro cell might provide coverage over a larger area, where there are multiple smaller cells underlying this larger coverage area. Such a configuration may be referred to as a heterogeneous network (HetNet). In this manner, users within the smaller cells share data resources amongst a smaller set of users and typically the HetNet configuration can provide higher capacity and a faster network overall.
A problem with smaller cells-larger cell interaction is that the more powerful (e.g., in terms of transmission power) larger cell can cause interference to the less powerful small cell and the user equipment being serviced by the smaller cell. One technique for reducing this interference is to provide almost-blank sub frames (ABSs) or low power subframes (LPSs), during which the macro transmits using relatively low power and a smaller cell schedules transmission and reception with user equipment which would have experienced an unacceptably high interference from the macro cell if the macro transmitted at full power. The macro and smaller cells coordinate the ABSs and LPSs.
Although ABSs and LPSs are an improvement over wireless networks without these techniques, interference mitigation for macro and smaller cells can still be improved.